This invention relates to appliances for use as aids for the deaf.
It is important to be able to impart hearing or the equivalent of hearing to hearing impaired people who have total hearing loss. For those persons with total hearing loss, there are no direct remedies except for electronic implants. These are invasive and do not always function in a satisfactory manner.
Reliance on lip reading and sign language limits the quality of life, and life threatening situations outside the visual field cannot be detected easily.
The present invention takes a novel approach to the provision of sound information to a user, using optical stimulation, and using the resolving power of the brain to distinguish sounds from an optical display which displays the sounds as a dynamic sonogram to the user.
There is anecdotal evidence that a blind person can xe2x80x9cvisualizexe2x80x9d a rough xe2x80x9cimagexe2x80x9d of his surroundings by tapping his cane and listening to the echoes. This is equivalent to the function of xe2x80x9cacoustic radarxe2x80x9d used by bats. Mapping of the human brain""s magnetic activity has shown that the processing of the xe2x80x9cacoustic radarxe2x80x9d signal takes place in the section where visual information is processed.
Many people who have lost their sight can read Braille fairly rapidly by scanning with two or three fingers. The finger tips of a Braille reader may develop a finer mesh of nerve endings to resolve the narrowly spaced bumps on the paper. At the,same time the brain develops the ability to process and recognize the patterns that the finger tips are sensing as they glide across the page.
In accordance with this invention, a method of presenting audio signals to a user is comprised of receiving audio signals to be presented, separating the audio signals into plural discrete frequency components extending from a low frequency to a high frequency, translating each of the frequency components into control signals, and applying the control signals to a linear array of light emitting devices for sensing by the user, and mounting the array on the head of a user where it can be seen by the user without substantially blocking the vision of the user.
In accordance with another embodiment, a sonogram display is comprised of a microphone for receiving audio signals, a circuit for separating the audio signals into plural discrete frequency components extending from a low frequency to a high frequency, an array of light emitting devices for mounting on the head of a user where it can be seen by the user without substantially blocking vision of the user, a circuit for generating driving signals from the components, a circuit for applying the driving signals to particular ones of light emitting devices of the array so as to form a visible sonogram.
The visual sonogram display can also be reduced to a single line of light sources with the linear position of light sources representing the different frequency components.
The distribution of frequencies along the line of light sources could have a linear (i.e. equal) frequency separation or a non-linear frequency separation such as a coarser separation in the low frequency range and a finer separation in the high frequency range. The non-linear separation should enhance the ability of the brain to comprehend the sound information contained in the sonogram that is displayed.
In such a single line of light sources mentioned above, the intensity of each frequency component can be represented by the output intensity (i.e. optical output power) of each light source corresponding to a specific frequency component. The intensity scale of each light source output could be linear in response to the intensity of the sound frequency component, or non-linear (e.g. logarithmic) in response to the intensity of the sound frequency component to enhance comprehension by the brain of the sound information contained in the sonogram that is displayed.
The linear array of light sources can be affixed to the frame of eyeglasses, in a position that does not interfere significantly with the normal viewing function of the eye. The alignment of the array can either be vertical or horizontal.
In order to facilitate easy simultaneous processing by the brain of the normal viewing function and the visual sonogram display, the linear array of light sources can be positioned so that the array is imaged on to the periphery of the retina. To enhance the visual resolution of the visual sonogram display, an array of micro-lenses designed to focus the array of light sources sharply on to the retina can be placed on top of the linear array of light sources.